1. Field of the Invention
Embodiments of this invention relate to lubricating compositions including high concentrations of magnesium and boron in the form of nanoparticles and to methods for making and using same.
More particularly, embodiments of this invention relate to lubricating compositions including high concentrations of magnesium and boron in the form of nanoparticles and to methods for making and using same, where the.
2. Description of the Related Art
Overbased magnesium compounds and methods for their production have been known for many years (see for example Hunt; U.S. Pat. No. 3,150,089; Sep. 22, 1964). They have been used in lubricants, as fuel additives in many combustion applications, and in various antifoulant additives used in refineries. These materials have been much sought after for these and many other as yet undiscovered applications.
Similarly, boron containing compositions have been researched from at least the same time period (see for example NACA Research Memorandum RM E55C07; June 1955) for its perceived value as a fuel and fuel additive. The splendid lubricating properties of boron formulations—especially boric acid—have also been widely investigated and are well known to those familiar with the art (see for example the early patent by Chapman; U.S. Pat. No. 905,649).
Attempts to combine the valuable lubricating properties of boron with various magnesium (and/or other alkali or alkaline earth metals) formulations have been ongoing since at least 1967 (see for example U.S. Pat. No. 3,313,727; April 1967; Peeler, R.). Combination products would theoretically combine the benefits imparted by each element. For example there is evidence suggesting that combinations of magnesium with boron would have enhanced properties as improved antifoulants in refinery use and examination of the high temperature region of the phase diagram of both magnesium and boron would suggest the combination of the two could be valuable as high temperature corrosion prevention additives.
Previously, attempts to produce combination compositions were constrained by the relatively low starting magnesium content of products researchers were required to use. This had the dual effect of forcing low magnesium concentrations as well as the amount of boron that could be reacted with the available magnesium compound was then necessarily low. This is a physical reality since the total composition must add up to 100%, the more “space” taken up by the low magnesium content materials; the less “space” is available for the boron containing material. Similar restrictions result from the even lower atomic weight boron. As is well known, boron is a very light element (low atomic weight). Therefore in order to obtain a viable, high boron content, any other element would need to be relatively dilute. This is so because associated molecular constituents of the boron compound would occupy large volumes of the combination product as the boron content is increased. Previous to this invention maximum starting magnesium contents might reach only 9 to 14 percent with concomitantly low resulting boron contents. The compounds of this invention conversely began as 30% magnesium containing liquids—more than double the previous levels—which allowed for a proportional increase in boron concentration.
Previous researchers were also constrained by the fact that most of those other magnesium compounds were comprised of stabilized magnesium carbonate overbases. Thus it was assumed and believed that only magnesium carbonate overbased materials could be boronated. The process of this invention has shown this is not a requirement. In fact it has been discovered there is no difference in reaction of previously carbonated materials and materials that have not been carbonate.
Similarly, nearly all previous patents concerning the combination of magnesium and boron have featured the prominent removal of water either formed during reaction or added as an ingredient at the start of the procedure. This in turn has led to the use of often hazardous, low boiling point liquids required to assist in the removal of the water. The difficult removal of water has in turn required the introduction of many antifoam products to try to assist the often violent distillation of water. The present invention has discovered that the removal of water is not necessary. It has additionally been found the retention of water has an additional benefit of maintaining all boron materials as boric acid. It is boric acid that has been found to have excellent lubricating properties. By the simple and desired retention of water, any boric oxide that forms is retained as boric acid by reconversion back to boric acid with water. Water may additionally be a catalyst to the ultimate reaction. By not needing to use low boiling solvents, there is no possibility they are present in final formulations. This allows for higher flash points which will make transport and use of any resulting materials safer.
By retaining the water in the reaction mass, it has also been found that the reaction can be run very quickly. It is only necessary to heat to about 100° C. which greatly facilitates any manufacturing process contemplated. Since the water is not removed, expensive heat exchangers and cooling facilities may be avoided.
3. Description of Related Art
Examples of the prior art are provided below to demonstrate some of the many methods previously developed. As will be seen nearly all methods require the use of multiple solvents, distillations, and/or multiple steps. They all differ greatly from the present invention due to the increased numbers of raw materials, solvents to be stripped, complex procedures, and in some cases very low alkaline earth and boron metal contents.
In U.S. Pat. No. 3,313,727 Peeler began with a lubricant base oil, a calcium petroleum sulfonate and then added sodium metaborate octahydrate. This mixture was then heated to partially dehydrate. The product was described as a “glass” which would not be equivalent to the flowable liquid product the present invention produces. No description of the metal content of this product was provided, but presumably it was relatively low and the glassy product would have only limited applicability and only for specialized uses.
In U.S. Pat. No. 3,853,772 Adams began with a lubricant oil, an alkali metal borate (previously produced by an undisclosed method and still containing various waters of hydration), added two dispersant materials—one of which contained an alkaline earth metal and sulfur. This was then heated to produce the product. No description of the metal content of this product was provided, but from an approximate mass balance, presumably it was relatively low.
In U.S. Pat. No. 4,683,126 Inoue mixed a neutral calcium sulfonate, a lubricant oil, powdered magnesium hydroxide, boric acid, water, and a cleaning solvent diluent. After processing to remove water and some of the solvent, a product resulted that was 7.7% calcium and 3.8% boron. Other metal contents were not described.
Fisher in U.S. Pat. No. 4,744,920 started with an overbased sodium carbonate sulfonate. To this was added a diluent oil, toluene, boric acid, and an overbased magnesium carbonate sulfonate. After processing to remove water and excess solvent a product containing 7.35% magnesium and 3.94% boron resulted.
In U.S. Pat. No. 4,900,854 Winterton began with rather exotic boron starting materials (bromo metal boranes was one) and worked at dry ice/acetone temperatures to produce a product that met his requirements. The procedure was too involved to be usable for large scale manufacturing procedures.
Erdemir, in U.S. Pat. No. 5,431,830 claimed boron compounds stabilized in solution by various dispersants are useful as lubricant compositions. He further maintained that boric acid possesses the lubricating properties to the extent that he wants to add materials—water—to convert any boric oxide preferentially back to the orthoborate form. He also states that smaller particles of boric acid are more effective as lubricant additives. However, in this patent he does not explain how to achieve these compounds, only that they are useful as lubricants.
In U.S. Pat. No. 5,854,182 Swami worked initially under strictly anhydrous conditions to produce a magnesium alkoxide material to which was subsequently added boric acid and a neutral calcium or magnesium sulfonate material. After heating this mixture, an alcohol byproduct was removed to provide a product (with magnesium sulfonate) containing 4.2% magnesium and 5.1% boron.
In U.S. Pat. No. 6,872,693 Cain describes a material that is produced from a complex mixture of monoalkyl benzene sulfonic acid, xylene, magnesium oxide, acetic acid, polyisobutylene succinic anhydride, methanol, and water. This was then blown with carbon dioxide. Many of these materials, lost during processing, were replaced and the mixture was again blown with carbon dioxide. After stripping solvents and water the final material contained 7.6% magnesium and 4.35% boron.
Robson in U.S. Pat. No. 7,026,273 utilized a lubricant oil already containing a magnesium or calcium material and added boron containing materials to this to produce products of extremely low (less than 0.5%) magnesium (or calcium) and boron (less than 0.2%) content. Presumably these low concentrations were all that was required for his applications.
In patent application 2008/0300426 Duchesne describes a product that begins with a calcium overbased material. To this was added xylene and methanol. This combined mixture was purged with nitrogen to remove all oxygen before adding a boron source. After stripping of solvents a material containing 7.7% calcium and 4.1% boron resulted.
In U.S. Pat. No. 7,479,568 Le Coent produced a material containing 9.4% calcium and 4.1% boron by combining xylene, methanol, calcium hydroxide, a sulfonic acid, boric acid, and a Group I oil. After suitable reaction and stripping of solvents the described material resulted.
In U.S. Pat. No. 7,547,330 Erdemir reveals a boron compound that when added to fuels imparts lubricating properties to engine parts. This composition consisted of a nanometer sized powder of an organic boron compound, e.g., trialkylborates, boroxins, or combinations of these. The thrust of his invention was exclusively to provide a lubricant composition. No mention was made of other applications. Curiously, although the claims of the patent do not encompass the use of boric acid, all of his example formulations illustrate only the use of boric acid. His formulation also relies heavily on mixing his aforementioned boron source material with a suitable lubricating liquid material.